/*
 * Copyright 2022 learn-netty4 Project
 *
 * The learn-netty4 Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package com.flydean31.http2framecodecserver;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http2.Http2SecurityUtil;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.ssl.*;
import io.netty.handler.ssl.ApplicationProtocolConfig.Protocol;
import io.netty.handler.ssl.ApplicationProtocolConfig.SelectedListenerFailureBehavior;
import io.netty.handler.ssl.ApplicationProtocolConfig.SelectorFailureBehavior;
import io.netty.handler.ssl.util.SelfSignedCertificate;
import lombok.extern.slf4j.Slf4j;

/**
 * HTTP2服务器
 */
@Slf4j
public final class CustHttp2Server {

    static final boolean SSL = true;

    static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8443" : "8000"));

    public static void main(String[] args) throws Exception {
        // 配置SSL
        final SslContext sslCtx;
        if (SSL) {
            SslProvider provider =  SslProvider.isAlpnSupported(SslProvider.OPENSSL)  ? SslProvider.OPENSSL : SslProvider.JDK;
            log.info("provider:{}",provider);
            SelfSignedCertificate ssc = new SelfSignedCertificate();
            sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey())
                    .sslProvider(provider)
                    //支持的cipher
                    .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
                    .applicationProtocolConfig(new ApplicationProtocolConfig(
                            Protocol.ALPN,
                            // 目前 OpenSsl 和 JDK providers只支持NO_ADVERTISE
                            SelectorFailureBehavior.NO_ADVERTISE,
                            // 目前 OpenSsl 和 JDK providers只支持ACCEPT
                            SelectedListenerFailureBehavior.ACCEPT,
                            ApplicationProtocolNames.HTTP_2,
                            ApplicationProtocolNames.HTTP_1_1))
                    .build();
        } else {
            sslCtx = null;
        }
        // 配置服务器
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.option(ChannelOption.SO_BACKLOG, 1024);
            b.group(group)
             .channel(NioServerSocketChannel.class)
             .handler(new LoggingHandler(LogLevel.INFO))
             .childHandler(new CustHttp2ServerInitializer(sslCtx));

            Channel ch = b.bind(PORT).sync().channel();

            log.info("使用支持HTTP/2的浏览器访问 " +
                    (SSL? "https" : "http") + "://127.0.0.1:" + PORT + '/');

            ch.closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
}
